Question: Express your answer as a mixed number simplified to lowest terms. $16\dfrac{1}{3}-12\dfrac{6}{7} = {?}$
Find a common denominator for the fractions: $= {16\dfrac{7}{21}}-{12\dfrac{18}{21}}$ Convert ${16\dfrac{7}{21}}$ to ${15 + \dfrac{21}{21} + \dfrac{7}{21}}$ So the problem becomes: ${15\dfrac{28}{21}}-{12\dfrac{18}{21}}$ Separate the whole numbers from the fractional parts: $= {15} + {\dfrac{28}{21}} - {12} - {\dfrac{18}{21}}$ Bring the whole numbers together and the fractions together: $= {15} - {12} + {\dfrac{28}{21}} - {\dfrac{18}{21}}$ Subtract the whole numbers: $=3 + {\dfrac{28}{21}} - {\dfrac{18}{21}}$ Subtract the fractions: $= 3+\dfrac{10}{21}$ Combine the whole and fractional parts into a mixed number: $= 3\dfrac{10}{21}$